Why do I have cockroaches in a clean house?

A clean house can still have cockroaches because they need water and shelter as well as food. They may enter through gaps, arrive in infested items or come in from outdoor hiding places. Small traces of grease or crumbs, leaking pipes and narrow spaces behind appliances can support activity even in a tidy home. (UC IPM: Cockroach identification and management)

Check behind the fridge, under the sink and around pipe openings, rather than only the visible floors and worktops. Fix leaks, store food securely and reduce gaps where cockroaches can enter or hide. Cleanliness helps, but identifying the species and finding its hiding places are also important. (UC IPM: Cockroach identification and management)